Liked the song itself, but in my opinion, having the (high pitch) vocals and snare/cymbals higher in the mix would add much. The bass drum feels a bit "flat" and obtrusive, a bit too much bass on it maybe. This is naturally all my opinion, production is quite the personal matter of course.

Structure/writing wise, this is fantastic, reminds me ALOT of Transylvanian hunger but with better production. Your high vocals could be louder for sure, they are really well done but they get lost in the mix because your guitar tone has so much midrange. Either you could scoop it a little or turn the high vox up. The lower vox are at a much more appropriate volume. Your drums could use some compression, the bass is pretty loud and the snare and cymbals are... not. The chuggy bits that come ~3:20 are a little thin tone wise, more low mids/bass would be ideal. Swell-y pad thing behing it sounds excellent. The trem picking/lead thing afterward could use a little more presence in the mix.

Keep in mind these are all just minor quips; overall this is really well done, almost sounds like its been mastered already